The X-rays cannot be diffracted by means of an ordinary grating because of______

Absolute alcohol cannot be obtained by fractional distillation because

Dilute HNO_3 cannot be concentrated beyond 68% by boiling because

When an electron in an excited state of Mo atom falls from L to K shell an x-ray is emitted. These x-rays are diffracted at an angle of 7.75^(@) by planes with a separationof 2.64A^(@) .What is the difference in energy between K-shell and L-shell in Mo. Assuming a first order dirffraction ? (sin 7.75^(@)=0.1349)